Dosage-dispensing devices with dosage units that normally include a source container and a dispensing head are used in particular for applications where small dosage quantities of, e.g., toxic substances are dispensed with high precision into small target containers. In many cases, the target container is placed on a balance in order to weigh the amount of substance dispensed from the dosage-dispensing device so that the latter can subsequently be processed further in accordance with a given purpose.
A dosage-dispensing device in which a dosage unit with a source container and a dispensing head can be emplaced is described in commonly-owned and co-pending US published application 2011/0220686. The source container is in essence a cylindrical container which, after having been filled with dosage material, is closed up with the dispensing head. The dispensing head includes a base unit which has an end surface and a coupling area for the source container or for a closure lid. Arranged in the end surface of the base unit is an outlet orifice which is connected to the coupling area. The dispensing head further includes a slide shutter which is held in a linear track in the base unit allowing guided movement parallel to the end surface. The slide shutter is controlled by an actuating member which is arranged on the base unit, rotatable about an axis that is orthogonal to the end surface, and includes a window, wherein for any position of the actuating member relative to the base unit, the outlet orifice lies within the area of the window. The slide shutter has a passage opening and is arranged between the base unit and the actuating member. By turning the actuating member relative to the base unit, the slide shutter can be moved in a straight line relative to the base unit and, in consequence, the aperture profile of the dispensing head can be varied as a result of the passage opening being shifted relative to the outlet orifice, and the stream of free-flowing material through the passage opening can be regulated.
In the operating position, the dosage unit installed in the dosage-dispensing device is oriented with the dispensing head facing downward and the outlet orifice located directly above the target container. The dosage unit therefore has to be already in the upside-down position when it is put into a seat of the dosage-dispensing device, or the dosage-dispensing device has to be equipped with seat that can be turned upside down and in which the dosage-dispensing unit can be secured by a restraining device against falling out.
A dosage-dispensing device with a seat for a dosage unit that can be turned upside down is shown in FIG. 6 of US 2011/0220686 which has already been cited above. After it has been set into the seat in upright orientation, i.e. with the dispensing head on top, the dosage unit is locked in place by a holder ring which can swivel, slide and be locked on a guide rod, before the seat is turned upside down, whereby the dosage unit is brought into the operating position.
Especially in the interest of operating safety, it appears highly desirable to automate the function of locking and unlocking the dosage unit and in particular to couple the locking/unlocking function with the turning-over of the dosage unit in its seat in such a way that it is absolutely impossible for the dosage unit to drop out of the seat. However, based on FIG. 6 and the accompanying description in US 2011/0220686 one has to conclude that the three steps of the securing procedure, i.e. the swiveling, sliding and locking of the holder ring have to be done manually by a human operator, before the seat with the dosage unit is turned upside down about a horizontal axis.
However, on closer examination of the securing concept with a holder ring that swivels, slides and locks on a guide rod, it is evident that a suitable actuating mechanism for this process would be relatively complicated and thus expensive. This clearly indicates a need for a fundamentally different concept to secure the dosage unit in the seat of the dosage-dispensing device.
Furthermore, in connection with the dosage-dispensing device of FIG. 6 in US 2011/0220686, it is proposed to loosen up the dosage material by turning the dosage unit in its seat about a horizontal axis repeatedly back and forth in alternating succession before the dosage-dispensing process. However, for the loosening of the dosage material as well as for separating it from the inside wall of the source container, shock movements are much more effective than the comparatively gentle turning-over movement about the horizontal axis.
A present objective, then, is to provide a dosage-dispensing device with a seat for a dosage unit, wherein the dosage unit that has been placed into the seat is secured by a holder device against falling out when turned upside down and can furthermore be subjected to a shock movement to loosen up the dosage material, wherein the holder device as well as the device for generating the shock movement are designed for a simple automated mode of operation.